fix(lambda.js): revert catch unhandled promise rejections

This reverts commit d06db15.

src/wrappers/lambda.js

@@ -111,17 +111,6 @@ function baseLambdaWrapper(
                 process._events.beforeExit = originalBeforeExit;
             });
         };
-        // catch an unhandled promise rejection within the user's code
-        process.once('unhandledRejection', (reason) => {
-            utils.debugLog('Unhandled Promise Rejection caught. Please handle the rejected promise');
-            const rejectedError = {
-                name: 'UnhandledPromiseRejectionError',
-                message: reason || '',
-                stack: '',
-            };
-            eventInterface.setException(runner, rejectedError, false);
-        });
-
 
         const handleUserExecutionDone = (error, result, sendSync) => {
             clearTimeout(timeoutHandler);

test/unit_tests/wrappers/test_lambda.js

@@ -100,7 +100,6 @@ describe('lambdaWrapper tests', () => {
             done() {},
         };
         consts.COLD_START = true;
-        process.setMaxListeners(0);
     });
 
     afterEach(() => {
@@ -278,17 +277,6 @@ describe('lambdaWrapper tests', () => {
         }, 1);
     });
 
-    it('lambdaWrapper: catch unhandled rejected promise', (done) => {
-        this.stubFunction = sinon.spy(() => {
-            // eslint-disable-next-line prefer-promise-reject-errors,no-new
-            new Promise((_, reject) => reject('Unauthorized'));
-            return 'success';
-        });
-        this.wrappedStub = lambdaWrapper.lambdaWrapper(this.stubFunction);
-        expect(this.wrappedStub({}, null, this.callbackStub)).to.equal('success');
-        done();
-    });
-
     it('lambdaWrapper: update COLD_START value', () => {
         consts.COLD_START = true;
         this.wrappedStub({}, this.context, this.callbackStub);